/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.dubbo.metrics.model;

public class TimePair {

    private final long begin;
    private long end;
    private static final TimePair empty = new TimePair(0L);

    public TimePair(long currentTimeMillis) {
        this.begin = currentTimeMillis;
    }

    public static TimePair start() {
        return new TimePair(System.currentTimeMillis());
    }

    public void end() {
        this.end = System.currentTimeMillis();
    }

    public long calc() {
        return end - begin;
    }

    public static TimePair empty() {
        return empty;
    }
}
